We often value people who act on their principles more than those who act solely on their preferences. In other words, we value behavior that is justified by reasons rather than emotions. This shouldn’t be much of a surprise to anyone. It’s ostensibly why people don’t like politicians who “flip-flop,” whether they be “liberal” or “conservative.” So, when people make decisions based on emotion, rather than reason, we think they are “biased” or “irrational.” (Knowles and Ditto call this the principle-preference dichotomy.) What’s strange, though, is that we often view our political opponents as emotional decision-makers, while we view people of our own political leanings as principled decision-makers.

The question Knowles & Ditto want to answer is, why?

They offer two reasons. First, they argue that this results from the “actor-observer bias”: the tendency to see one’s own actions as based on beliefs and others’ as based on desire. Imagine, for example, Political Candidate is running for office. Her platform is to “make government smaller by cutting taxes and entitlement programs.” When Margo decides to support Political Candidate, Margo thinks she does so because of her beliefs about small government. Jim, on the other hand, views Margo’s behavior as merely reflecting her desires. Jim might say that Margo supported Political Candidate merely because she will receive more money in tax breaks while Margo might claim she dislikes lots of government regulation. The reason for the discrepancy, according to the authors, is one’s access to mental states: Margo has access to her own mental states (sort of), and Jim does not. Margo’s view of her own behavior is therefore privileged; Jim’s is epistemologically impoverished. As a result, she views her own choice as one of principle while Jim views it as one of desire.

Further reinforcing this view is individuals’ desire to see themselves and members of their group positively. As the authors note:

[T]he preference-principle dichotomy is powerfully reinforced by individuals’ desire to hold a positive view of themselves, as well as of others who share their attitudes and group memberships.

To achieve this end, people become “naive realists,” perceiving themselves as “reasoned and free from bias.” In other words, individuals view their own attitudes as “reasoned,” “objective,” and, therefore, principled. That provides them with a much more flattering picture of themselves than one in which they make decisions based (solely) on preferences. Forget the somewhat false dichotomy for a moment and just ask yourself: Do you see yourself as someone who makes reasoned, as opposed to emotional, judgments? Do you see those who disagree with you differently?

There’s still a problem, though. Individuals often seem to be seeking self-interested goals while offering principled reasons. This

should, at least in principle (no pun intended), destroy the “objectiveness” people purport to adhere to when making decisions. Put another way, one must at least appear to be objective to gain credibility (with themselves or others). Preserving this appearance happens in two ways. First, we approach judgments “without an explicit sense that we are trying to construct a justification for one conclusion over another.” Instead, our “preferences” are part of cognitive structures: satisfying them produces greater coherence than not satisfying them. So, many times our interpretation of information produces preference-satisfying conclusions.

Second, our cognitive structures can lead us to preference-satisfaction in another, sometimes unconscious way: “‘shifting the standards’ by which a preferred conclusion is defined.” Because we do this somewhat intuitively and seemingly without pretense, Knowles & Ditto call it implicit casuistry. By this they mean there are “circumstances in which individuals unwittingly select principles that happen to provide intellectual justification for preferred conclusions.” We are not good at being conscious reaonsers, always assessing problems objectively. Our brains select principles that cohere with our preferences. The principles–by way of implicit casuistry–serve in some ways to mask our preference-seeking behavior.

The reason implicit casuistry seems to work so well is because all ideologies seems equally susceptible to it. Indeed, small changes in factual situations can influence the way people use different standards. The authors give examples where subjects use either deontological (or rights-based) standards and consequentialist standards to justify certain behavior or conclusions. They show that people, regardless of their political preferences, will employ these reasoning strategies depending on the outcome that best accords with their political preferences.

Moving into the legal realm, Knowles & Ditto note that people’s views of judicial decisions often correlate with the extent to which the decision satisfies their preferences. They also note that judges may manipulate canons of constitutional interpretation to server various preferences. That, of course, is in line with a mature body of scholarship on judicial behavior. Scholars like Lee Epstein, Thomas Walker, Michael Giles, Ryan Owens, Ryan Black, et al. have shown that judges often seek policy preferences when deciding how to resolve a particular case.

Of course, casuistic reasoning occurs in other domains as well. Knowles & Ditto show how casuistic reasoning occurs in the context of race. Political preferences influence how people react to and justify their decisions when race becomes an issue. They note that frequently scholars disagree about why people hold particular racial attitudes. Some scholars claim disagreements of principle cause rifts; others claim that the disagreement results from claims to competing claims for finite goods (e.g., wealth, education). Knowles & Ditto argue it’s both:

The illusion of contraction may fade if one adopts a casuistic-reasoning model in which principles are frequently brought to bear dynamically in support of preferences.

In other words, people may use principles to justify their racial preferences. “Colorblindness,” for example, may serve as the principle that justifies an opposition to affirmative action.

In concluding, the authors note that casuistic judgments may have temporal effects. That is, using one principle may increase the probability of using that principle in the future. In lawyer speak, we might say people have a built-in stare decisis mechanism; it’s just not clear how strongly it operates in various situations or across time. Knowles & Ditto also are careful to explain that casuistic judgments are not per se illegitimate. (Here they venture into philosophy, essentially taking an hedged intuitionist stance.) Their claim is that attitudes are likely based on some form of intuition, and that intuition isn’t–in and of itself–a reason to reject a claim. For this reason, they argue that casuistic judgments may be legitimate.